(It is said unto them): This is (your plight) because, when Allah only was invoked, ye disbelieved, but when some partner was ascribed to Him ye were believing.
(Yang demikian itu) maksudnya, azab yang kalian sedang jalani itu (adalah karena) ketika di dunia (kalian kafir apabila Allah saja disembah) artinya, kalian kafir bilamana Dia diesakan. (Dan apabila Allah dipersekutukan) menjadikan sekutu bagi-Nya (kalian percaya) kalian percaya kepada kemusyrikan itu.